We just got back from a CYOA charter two weeks ago. Based on the needs you describe, I would suggest planning to spend Monday night in Maho or Francis. An easy point for drop off and pick up would be the area near the Maho Crossroads. It's easy to identify for a taxi driver, and relatively accessible by dinghy. You will need to land the dingy at the northern end of the Maho beach, via the dinghy channel. The road is very close to the beach there, making it easy for crew to get luggage back to the boat.